1. Field
The field relates to an organic light emitting diode (OLED) display. More particularly, the field relates to an OLED display that reinforces adhesive force of a cell seal adhering adjacent substrates.
2. Description of the Related Technology
An OLED display includes a plurality of OLEDs each of which includes a hole injection electrode, an organic emission layer, and an electron injection electrode, and light is emitted by energy that is generated when an exciton that is generated by recombination of electrons and holes falling from an excited state to a ground state within the organic emission layer.
The OLED display has sub-pixels in a matrix format in a display area, and the sub-pixels each include an OLED and a driving circuit unit. The driving circuit unit includes a switching transistor, a driving transistor, and a storage capacitor.
The OLED display may be individually manufactured, or a plurality of OLED displays may be manufactured for productivity improvement. A base substrate (or, an array substrate, hereinafter referred to as a base substrate) has a plurality of unit cells between front and rear substrates. Herein, one OLED display is a unit cell, and hereinafter will be referred to as such.
A cell seal is provided between front substrate and the rear substrate to adhere the two substrates. As one example, the cell seal may be formed of a glass frit. The glass frit is applied to a top light emitting type of OLED display that realizes high resolution, and effectively prevents transmission of external moisture or oxygen into the unit cell.
Although a cell seal formed of the glass fit can block external moisture or oxygen extremely well, it also generates thermal shock or stress due to mismatch in thermal conformity with the main glass (i.e., a front substrate or a rear substrate). Accordingly, mechanical strength of the base substrate or the OLED display is weakened.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.